Supporting trough



Feb. 27, 1962 R. F. E. BUNSTON SUPPORTING TROUGH 5 Sheets-Sheet 1 1Filed July 21, 1959 UUEEEEE FL .I

INVENTOR Roy 5 E. BunsTon AZwL M A TTOR VEY R. F. E. BUNSTON SUPPORTINGTROUGH Feb. 27, 1962 5 Sheets-Sheet 2 Filed July 21, 1959 INVENTOR 20715 5uns7on BY 4 TTORNEY Feb. 27, 1962 R. F. E. BUNSTON SUPPORTING TROUGH5 Sheets-Sheet 3 Filed July 21, 1959 HIUHIUUUHIUHUUHIUD IN V EN TOR RoyE E. BunsTon EUODDDDDUEDD:

BY .JiMZM A TTORNEY Feb. 27, 1962 R. F. E. BUNSTON SUPPORTING TROUGH 5Sheets-Sheet 4 F I G .l4

Filed July 21, 1959 FIG .9

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' I SUPPORTING TROUGH Filed July 21, 1959 5 Sheets-Sheet s FIG.IO

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' IN V EN TOR. Roy E E. Buns'lbn IZZ 14 TTORNEV United States Patent3,022,972 SUPPORTWG TRGUGH Roy F. E. Bunston, Markham, Ontario, Canada,assignor to Burndy Corporation, a corporation of New York Filed July 21,1959, Ser. No. 828,638 8 Claims. (Cl. 24868) This invention relates tosupporting trough and, more particularly, to cable or pipe tray unitswhich may be joined to form a unitary supporting trough system.

Cable and pipe supporting trough systems are extensively used in powerstations and large industrial plants to support a plurality of cables orwires for the transmission of electrical energy and for the support ofpiping or tubing used in the transmission of fluids both liquid andgaseous. Usually, a plurality of prefabricated channel or tray units areassembled at the plant location to form the supporting trough system.

In the past the prefabricated cable tray units have generally been oneof two forms. The first type may be designated as a mesh channel unit.Such mesh units included a bottom for the trough which was usuallymanufactured of expanded sheet metal. The expanded metal bottom wasjoined along its longitudinal edges to channel supports or side rails.In one embodiment of this type of mesh channel unit, the expanded metalbottom had its edges upturned to provide side walls for the trough. Theupstanding edges of the expanded metal were finished ofi by attaching asheet metal binder strip to the edges of the wall in order to present asmooth lip which would not cut into the cable.

The second type of channel unit may be designated punched sheet metaltype channel unit. The channel unit of this known type was generallyformed of a single sheet of metal in which the sides of the trough unitwere constructed by forming or bending the two opposite portions of thesheet metal bottom to form the upstanding walls. Transverse slits werepunched in the bottom of the unit intermediate the wall portion and theedges of the slots were downwardly extruded to provide a rounded lip foreach of the slits.

The mesh type of channel unit provided a substantial air fiow throughthe openings in the bottom and the slits in the punched sheet metal typeprovided a similar but somewhat lesser flow of air. The mesh unit wasdifficult to interconnect to other units while the downward turned edgesof the slits in the punched sheet metal type often interfered with theeasy support of the trough system. Both types of units required arelatively heavy gauge of metal to be used in order to support theweight of the cable and piping carried by the system and to allow for aproper margin of safety in the event that workmen used a trough as acatwalk during construction of the plant or building in which it wasinstalled. In addition; the required heavy metal gauge made theprefabricated unit quite heavy and awkward to handle duringinstallation.

In certain locations it is necessary to install covers for the troughunit to prevent the accidental dropping of tools 7 'iee a new and novelsupporting trough unit which is materially stronger than the prior artunits described.

Another object of this invention is to provide a new and novel cabletray unit which is substantially lighter in weight than known types oftrough when comparedto units of equal supporting strength.

Still another object of this invention is to provide a new and novelsupporting trough unit which provides for both a transverse and verticalair circulation around the supported elements.

Further objects of this invention provide for the ease of attachment ofcables or piping to the trough structure; for the ease of support of theassembled system and in general for all the advantages of the knowntrough units in addition to unique advantages unknown in the Prior artwhile overcoming the disadvantages of the known supporting troughsystems.

According to the present invention, the cable tray unit comprises abottom and two longitudinally extending supporting channels. The bottomof the tray comprises a ribbed floor having alternating ridges andgrooves. The ridges extend the full transverse width between the sidechannels to provide additional strength to the floor as a result of thisbeam effect. The grooves between the ridges include a plurality ofcut-outs or holes intermediate the side channels to provide for verticalair flow and for the clamping or lashing of the wires, cables or pipesto the tray unit.

The supporting channel side elements include formed stiffening ribelements which longitudinally extend the length of the tray to provideadditional strength in the longitudinal direction. The side railsinclude folded over or formed top elements to materially increase thestrength and to protect the ends of screws utilized in attaching coversto the tray element.

The above-mentioned and other features and objects of the invention willbecome more apparent by reference to the following description taken inconjunction with the accompanying drawings, in which:

FIG. 1 is a plan view of the ribbed bottom for use in the cable troughof this invention;

' FIG. 2' is a cross-sectional view of theribbed bottom taken alonglines 2-2 of FIG. 1;

FIG. 3 is a perspective view of the side rail for use in the cabletrough of this invention;

FIG. 4 is a perspective view of the cable trough units assembled to forma cable trough system in accordance with the principles of thisinvention;

FIG. 5 is a perspective view of part of a cable trough system utilizingthe cable trough units of this invention;

FIG. 6 is a perspective View partly in section showing the means forjoining the cables to the cable trough units;

FIGS. 7, 8, and 9 are various embodiments of bend section units for usein conjunction with the cable trough units of this invention;

FIG. 10 is one embodiment of a cross connector for use in assembling acable trough system;

FIG. 11 is a partial view in perspective of the supporting element foruse in the cross connector of FIG. 10;

FIG. 12 is an alternate embodiment of a cross connector for use in acable trough system;

FIG. 13 is a perspective view partly in section of a corner support foruse with accessories used in the cable trough of this invention;

FIG. 14 is a plan view of a reducer section for use with the cabletrough system of this invention;

FIG. 15 is a perspective view of a ladder type cable trough inaccordance with the principles of this invention and FIG. 16 is a crosssectional view of the cable trough unit of this invention with a coverattached.

Referring to FIGS. 1 and 2 of the drawing, a cable tray bottom member 16for use in the cable tray unit of this invention is therein shown tocomprise a plurality of alternating ridges l2 and grooves 1 Each ridge12 had a flat floor section 16 joining the vertically depending sideflanges 18. The ridge sections 12 extend the full width of the bottom10. The groove section 14 joins the bottom of the vertically dependingflanges 18 of the ridge 12. A plurality of spaced connecting strips 29join the depending flanges l8to form a plurality of openings or holes 22which may. be punched out of or otherwise formed in the grooves 14 tofashion the connecting strips 29. The connecting strips 26 provideadditional support against transverse forces.

Referring to FIG. 3 of the drawing, one of the side rails 24 for use inthe cable tray unit of this invention is therein shown to comprise arolled steel form having a horizontal member or supporting lip 26 and avertical member or side wall 28. The vertical side wall 28 has alongitudinally extending integral stiffening rib 36 formed therein toprovide a beam effect which materially assists in resisting deformationin an axis perpendicular to the longitudinally extending axis of theside rail 24. The upper portion of the vertical side wall 28 is turnedin on itself and folded over the provide a finished edge 32 having alongitudinally extending hollow of rectangular cross section 34. The end36 of the side rail 24 is formed in such a manner that it is slightlyspaced apart from the vertical side wall 28. Such spacing permitscomplete galvanizing or otherwise plating to protect the entire siderail 24 against corrosion. However, when forces due to the weight of thecables or pipes supported are applied to the lip 26, the silght openingbetween end 36 and wall 28 tends to close, providing additionalresistance to deflection of the side rail 24. An additional stiffeningrib 38 is formed where the lip 26 meets the vertical wall 28. Thecombination of the folded over end 32 and the stifienin ribs 30 and 38provide a strengthening section modulus which, combined with the ribbedflooring provides great rigidity, both longitudinally and transversely.

Referring to FIG. 4 of the drawing, the assembled cable tray of myinvention is therein shown to comprise a pair of side rails 24 similarto those illustrated in FIG. 3 and a bottom member as shown in FIG. 1which is integrally joined to the lips 26 of'the side rails 24 by meansof spot welding in the groove margins as shown by reference numeral 40or otherwise attaching the ribbed bottom 10 to the side rails 24. Eachsupporting trough unit is terminated by coupling means 42 so that theymay be easily assembled to form continuous length of trough.

The coupling means illustrated comprises mating hinge elements 44 and 46attached to the ends of the side rails 24 of each trough unit 48, 50 and52. The mating hinge units 44 and 46 are positioned in such a manner asto cause their coupling elements 54 to interleave and a coupling pin isinserted to join the side rails ends as shown at 58. It is, of course,obvious that other coupling means can be utilized to join the cable trayunits.

The ribbed floor 10 of the trough units with its plurality of ridges 12extending between the side rails 24 act as beam members providing amaximum resistance to transverse deflection, giving a maximum strengthto the entire unit. The stiffening ribs 34 and 38 in addition to thefolded over portion 36a of the side rails provide rigidity along thelongitud nal axis of the unit. Due to the additional -strength provided,the supporting trough of my invention has equal or better strength whencompared to the prior art units. For example, in order to support 100pounds of pipe or cable plus a workman on a 24 inch Wide trough, theprior art units found that it was necessary to use a 14 gauge metal informing the trough. The supporting trough of this invention can supportthe same load by using 20 gauge metal for the bottom with 16 gaugematerial for the side rails. In general, the prior art devices having amesh bottom were 15% heavier than the cable tray of this invention. Thislighter weight makes this trough easier to install, more economical andallows it to be supplied in longer lengths than the prior art units.

Again referring to FIG. 4 it is seen that units 48 and 50 may be joinedwithout the use of any joiner strip. The unique design of the ribbedbottom 10 permits the tray units to be out along a groove 14. Since thepipe or cable rests on the floor 16 of the ridges 12 the supportedelements do not come in contact with the cut edge and this eliminatesthe danger of damaging the cable insulation eliminating the need for ajoiner strip.

As shown in FIG. 5, the assembled trough units may be supported by meansof a hanger fixture 60 of the trapeze type depending from an overheadsupport. Since no portion of the trough depends below the lips 26 of theside rails 24, an even undersurface is achieved which allows ease insupporting the unit. Alternately, the trough units may be supported by acantilever beam 62 supported by an insert 64 mounted to the verticalwall. The cantilever beam 62 is terminated by an upstanding lip 66 en.-gaging the side wall 28 and end 32 of the rail 24 and preventinginadvertent lateral movement of the trough units.

Referring to FIG. 6 there is therein shown various means for attachingthe pipe or cable 68 and 70 to the tray bottom 10 of this invention. Thesupported pipes or cable 68 and 7t rests on the elevated portion 16 ofthe ridges 12 formed in the ribbed floor 10. A cable clamp 72 ofstandard size and shape may be inserted in the openings 22 formed in thegrooves 14 on the ribbed door It). The nut and bolt 74 of the cableclamp 72 are tightened to firmly grasp the cable 68 and resist move.-ment transverse to the axis of the tray. Alternately, the cable may belashed to the connecting members of the grooves by means of a cord orwire 76. Thus the cables may be attached either to the opening 22 or tothe com necting strips 20 as is deemed most desirable for the particularapplication. It is also apparent from'FIG. 6

that vertical air circulation is provided through the open.- ings 22 inthe ribbed bottom 10 and around the cables by air flow in the grooves14. These mutually perpendicular air currents tend to provide adequatecooling for the cable.

In order to provide accessory units for the cable tray system of thisinvention so that they may be formed into a system, various accessoriesare shown in FIGS. 7-14.

FIG. 7 illustrates one method of providing a bend to join two straighttray units to change the axial direction of the system. The bend of FIG.7 is formed of two curved side rails 78 and 80 and a ribbed bottom 82.The bottom unit 82 is formed of wedge shaped ridges 84 and radiallyextending grooves 86. The width of the grooves 86 is maintained constantso that the same punch equipment utilized to form the grooves inflooring 0* the straight units may be used in forming the curvedflooringof FIG. 7. The sheet metal bottom 82 is placed under the punchto form the first groove and the material is then rotated and moved toform the successive grooves in the bend. The bottom 82 is integrallyjoined to the side rails to form the bend. In order to provide for easeof attachment the Wedges are formed with a depressed portion 86 whereadditional spot Welding is utilized to form a more rigid unit. It hasbeen found where the width of the bend is increased, additional air Howis advantageous. In order to provide this additional air flow auxiliaryradial grooves 88 are formed in the wedge-shaped ridges of the bend.These-auxiliary radial grooves 88 do not extend the full length of thefloor but are incorporated in the width portion of the wedge shapedridges. It is, of course, realized that whereas the bends illustratedhave their inner and outer side rails curved about a common center, itis equally possible to form these side rails with a'common radius sothat the curves or bends will smoothly fit together in a horizontalplane.

Referring to FIG. 9 of the drawing, an alternate embodiment of a bend 90is therein shown to comprise a plurality of straight section rib floors92 and 94 which have been cut to form the bend-90. A corner brace 96similar to the brace illustrated in FIG. 13 and hereinafter described isutilized to provide the support between the inner side rail 78a and thestraight sections 92 and 94 of the ribbed flooring.

Referring to FIG. 10, one embodiment of a crossconnection is thereinshown to comprise a plurality of straight ribbed flooring sections 98,99, and 100 which have had their corners removed and are supported by abrace 102 similar to that shown in FIG. 11. The brace 102 is joined atits ends to the lips of the paired rails 104, 106 and 108, 110, andprovides a supporting lip 112 to which the ends of the straight ribbedfloor bottoms 98 and 100 are joined. The lip 112 of the supporting brace102 is integrally formed with a reinforcing ridge or beam section 114which fits under the end ridge 116 of the ribbed flooring section 98while the lip 112 supports the end of flooring sections 100.

Alternately, straight sections of ribbed flooring 118, 120 and 122 maybe utilized to form a cross connector such as illustrated in FIG. 12which is composed of the ribbed flooring section, four curved side rails124 are joined at their outer extremeties to the straight ribbed floorsections and corner brace 126 such as illustrated in FIG. 13. The cornerbrace 126 used in conjunction with ribbed flooring sections includes asupporting beam 128 and a corner 130. The corner 130 formed with a lip132 which is utilized to support the side of straight section 102 inFIG. 12 or the edge of straight section 92 in FIG. 9. The depressedportion 134 of the corner 130 is spot welded to the lip of the innerside rail. A support member 136 has its ends joined to the lips of theside rail and supports the corner 130. The lips 138 of the supportmember are utilized to support the edge of the straight ribbed floorsection 118. Thus the silled floor sections are supported on the lips132 and 138 of the corner base member 126.

FIG. 14 illustrates one embodiment of a reducer section 140 for joiningwide and narrow straight trough sections. The reducer section iscomposed of a ribbed floor section 142 cut to the desired width and onestraight rail section 114 and a bent rail section 146. The rail sections144 and 146 are similar to the rail illustrated in FIG. 3 and the rolledbottom 142 is joined thereto.

Referring to FIG. 15 an embodiment of a ladder type cable trough 148 istherein seen to comprise a pair of side rails 15!) and 152 similar tothe side rails illustrated in FIG. 3 integrally joined by a plurality ofspaced bracing ladder rungs 154. Each ladder rung 154 is ribbed orcorrugated to form a plurality of beam units having flat floor sections156 joining depending flanges 158. A plurality of interconnecting strips160 join the bottom edges of the depending fianegs 158 of the rungs 154to form the grooves sections. The rungs 154 are integrally joined to thelips 162 of the side rails 150 and 152 to form a continuous ladderstructure.

Due to the beam effect of the rungs 154 and the stiffened side rails 150and 152 the unit illustrated in FIG. 15 achieves substantial rigidityagainst vertical and transverse deflection.

Referring to FIG. 16 it is often desirable to append a cover to thecable tray of this invention. Since the edges 164 of the side rails arefolded over to provide a flat top surface enclosing a protected hollowsection, it is merely necessary to place a sheet metal cover 166extending between the folded over edges 164 and use sheet metal screws168 to join the cover 166 to the side rails. The ends of the screw 168are disposed within the hollow of the folded edges and are thusprevented from damaging the cables inadvertently. Alternately the covermay be formed with a lip 170 and the screw 172 inscrted from the side.

. I have thus described my invention, 'but I desire it understood thatit is not confined to the particular forms or uses shown and described,the same being merely illustrative, 'andthat the invention maybe carriedout in other ways without departing from the spirit of my invention, andtherefore, I claim broadly the right to employ all equivalentinstrumentalities coming within the scope of the appended claims, and bymeans of which, objects of my invention are attained and new resultsaccomplished, as it is obvious that particular embodiments herein shownand described are only some of the many that can be employed to attainthese objects and accomplish these results.

I claim:

1. A supporting trough, comprising: a pair of spaced apart,longitudinally extending side rails; each rail comprising a verticalmember and a horizontal member; a plurality of longitudinally spacedapart transverse beams interconnecting said pair of side rails; saidplurality of beams comprising a plurality of vertical members and aplurality of upper and lower horizontal members alternatelyinterconnecting the upper edges of adjacent vertical members and thelower edges of adjacent vertical members; each end of each said lowerbeam horizontal member overlapping a rail horizontal member and attachedthereto.

2. A supporting trough according to claim 1 wherein each said lower beamhorizontal member has a plurality of holes formed therein.

3. A supporting trough according to claim 1 wherein said vertical andhorizontal members of said rails are flat plates each joined to theother along an edge thereof; said vertical plate being divided into aminor portion adjacent the free edge of said vertical plate, and 'amajor portion adjacent the edge attached to said horizontal plate, saidminor vertical plate portion bent out of the plane of said verticalplate, first in a direction normal to the vertical plate plane andtowards the center of the trough, then parallel to the vertical plateplane and towards the center of the trough and finally normal to thevertical plate plane and towards said vertical plate plane, said freeedge being located adjacent yet spaced from said major vertical plateportion.

4. A supporting trough according to claim 1 wherein said horizontal andvertical members are provided by a single sheet of metal bent into anL-shaped cross-section, said horizontal member being below said verticalmember.

5. A supporting trough, comprising: a pair of spaced apart,longitudinally extending side rails; each rail comprising a verticalmember and a horizontal member; a trough bottom between said pair ofrails comprising a corrugated sheet having transverse parallel, spacedapart corrugations extending from sheet edge to sheet edge, saidcorrugations forming said sheet into spaced apart transverse verticaland upper and lower horizontal elements; the ends of said sheet lowerhorizontal elements overlapping and attached to said rail horizontalmembers.

6. A supporting trough according to claim 5 wherein each said sheetlower horizontal element has a plurality of holes formed therein.

7. A supporting trough according to claim 4 wherein said vertical andhorizontal members are flat plates each joined to the other along anedge thereof; said vertical plate being divided into a minor portionadjacent the free edge of said vertical plate, and a major portionadjacent the edge attached to said horizontal plate, said minor verticalplate portion being bent out of the plane of said veiti'cl ialt, fi'rst"in 5 dii'btibh fibir'hel 't?) 'th iiftiiil pllte plane and tbwards thecenter 6f the tru'gh, then parallel to the vei'tical 'plate plane afidtowards the efitei Of the trough and finally normal t6 the vertical'plate 'pl'a'n hd towards said 've'rtical plate plane, "said free edgebeing located adjacent yet spaced from said mjor verfica-I plate por tion.

8. A supporting trough ae'cbrdin'g {0' elai'm 5 wherein said horizbntland vertical members are provided by a single sheet of metal hen; intoan 'L' shped 'crbseetion, Sid horizontal member being belbw 893d 'Vfticlihem= ber.

Reta-mesfined 'an the me bf this patch UNITED STATES PATENTS

